The present invention relates to an artificial vessel having a porosity, a compliance approximate to that of a vital vessel, and a contact surface with blood having an excellent blood compatibility. More particularly, the present invention relates to an artificial vessel having a porosity, a compliance approximate to that of a vital vessel, and a contact surface with blood having an excellent blood compatibility.
In recent years, study on the artificial vessel has proceeded with a progress of vascular surgery and many artificial vessels have been developed. Hitherto, for an artificial vessel for artery of a medium- or large-caliber with a diameter of about not less than 6 mm, Debakey artificial vessel made of woven Dacron (USCI. Co., Ltd. of U.S.A.), Gore-Tex (Gore Co., Ltd. of U.S.A.) which is made of an expanded polytetrafluoroethylene (hereinafter referred to as "EPTFE"), and the like have been clinically used.
The above artificial vessels have pores which communicate the inside and the outside of the vessel wall. Soon after the artificial vessel is grafted into a living body, the vessel is covered with pseudointima and the pseudointima grows into the communicating pores, which makes the artificial vessel encapsulated to serve as the artificial vessel. Such property of having the communicating pores suited for encapsulation is hereinafter referred to as "porosity".
However, these artificial vessels have a disadvantage of a poor patency since they have a mechanical property, especially a compliance extremely different from that of a vital vessel and a contact surface with blood having a bad blood compatibility. From this reason, they cannot be clinically used as the artificial vessel for vein or in a vascular reconstructive surgery of artery of a small-caliber with an inner diameter of not more than about 6 mm and autogeneous vein grafts have hitherto been employed in vascular reconstructive surgery of arteries below knees or of coronary artery.
For obtaining the artificial vessel having an excellent patency, especially the artificial vessel suited for application in the vascular reconstructive surgery of arteries of small-caliber, it appears to be important for the artificial vessel to have a mechanical property, especially a compliance approximate to that of a vital vessel and to have a contact surface with blood having an excellent blood compatibility as well as to have a porosity, which improves the patency of the artificial vessel. However, such artificial vessel has hitherto not yet been prepared.